Owing to their small size, it is often difficult to precisely align and attach optoelectronic devices, such as a semiconductor chips, to fiber optic couplers. A gallium arsenide die chip, comprising a twelve channel Vertical Cavity Surface Emitting Laser (VCSEL) can be etched with a number of V-shaped grooves on the laser-dotted surface. A similar etching procedure can provide V-shaped grooves at mating locations on an end face of a coupler. Raised pins, or V-shaped ribs, can be inserted into the V-shaped grooves disposed on the coupler surface, which interlock with the etched features on the VCSEL surface. These interlocking pins provide perfect self-alignment between the two parts when they are brought into contiguous contact. The mating parts can then be permanently attached with epoxy or flexible adhesive.